The present invention relates generally to packaging equipment, and more particularly to a film splicer. Specifically, the film splicer of the instant invention is particularly useful for splicing (or joining) the ends of successive rolls of center-folded films of the type typically used for heat shrink film wrapping devices, such as side-seal heat shrink film wrapping devices.
Wrapping devices and side-seal heat shrink film wrapping devices, in particular, are well known in the art. Such wrapping devices may be used to wrap a variety of products, such as magazines, pads of paper, light bulbs, video tapes, CD-ROMs and pharmaceutical products.
Side-seal heat shrink film wrapping devices operate using films, which may be made of polyolefin, polyvinyl chloride (PVC), polyethylene or other materials as are known in the art. In many heat shrink film wrapping applications, such films are center-folded, meaning that the film is folded in half along its width to create a folded film that has upper and lower layers (or “legs”) of approximately equal width connected at the fold.
Such center-folded films generally are wounded and stored on rolls in their folded state. The films are fed into wrapping devices and opened (or unfolded) sufficiently to permit the product to be wrapped to be disposed between the upper and lower legs of the film. In this manner, the fold between the upper and lower legs of the film acts to seal one side of the product, while the wrapping device seals the remaining three sides of the product, typically through the use of an elongated heating element (or combination of heating elements) that engages the unsealed sides of the film and seals the film onto itself. The wrapped product is then passed through a shrink tunnel where the film is heated to a sufficient temperature for a sufficient time so as to shrink the film around the product in a desirable manner.
In prior art heat shrink film wrapping devices, when the center-folded film roll being fed into the wrapping device is depleted (that is, when all of the film stored on the roll has been used), operation of the wrapping device (and the entire packaging line) must be suspended while a new roll of film is mounted and the new film is fed (or threaded) through the wrapping device. At this point, operation of the wrapping device (and the packaging line) may be resumed.
The downtime associated with reloading film rolls into wrapping devices can be significant, and much of this time can be attributed to the time spent feeding (or threading) the film from the new roll of film into the wrapping device. This time decreases the efficiency and speed of the overall packaging process and increases costs. What is needed, therefore, is to reduce the downtime associated with changing film rolls by eliminating the need to thread the film of the new film roll through the wrapping device.
Specifically, there is a need for a film splicer that is specifically adapted to operate with side-seal heat shrink film wrapping devices that use center-folded films. Desirably, such a center-folded film splicer is configured to splice (or join or seal) the ends of center-folded films on successive film rolls such that the trailing end of the film from a depleted film roll is spliced (or joined or sealed) to the leading end of the film of a fresh film roll so that the film from the fresh roll is automatically threaded through the wrapping device.
More desirably, such a center-folded film splicer is configured to simultaneously splice (or join or seal) both the upper and lower legs of a center-folded film. More desirably still, such a center-folded film splicer comprises a splicing assembly that is advantageously and conveniently slidably mounted on the side-seal heat shrink film wrapping device such that it may be moved into and out of an operating (or splicing) position as needed so as not to interfere with the path of the film during operation of the wrapping device. The present invention satisfies these needs.